Malattie oculari ereditarie negli animali d’affezione: approccio clinico, diagnostico e terapeutico

Objective: To describe the epidemiology and the types of eye disorders that are presumed to be inherited (PIED) in canine and feline breeds. Methods: The medical records of the animals subjected to a specialist ophthalmological examination were selected between 2017 and 2022. The prevalence of presumed inherited eye disorders with 95% confidence intervals was reported for dogs and cats enrolled. Mean, median, range, first and third quartiles, and percentages were reported for the numeric, percent, and frequency data for categorical variables. The period prevalence (2017-2022) of PIED in dogs and cats was calculated as a function of the total number of the same and the total number of animals affected by eye lesions (PIED and non-PIED) examined belonging to the same species; the frequency (%) of PIED lesions in the single breed of dogs and cats was also analyzed. The prevalence of PIED was also reported in relation to the four age groups in which the subjects examined were divided. Fisher's exact test was applied to verify the proportion of canine and feline breeds affected by the individual diseases diagnosed from 2017 to 2022 compared to the proportion of the same breeds in the total population of dogs and cats visited in the same period. Values of P <0.05 were considered significant. Furthermore, the Student's t test for unpaired data was applied to make a statistical comparison between the data of the three-year period 2020-2022 and the previous three-year period (2017-2019), in order to highlight any differences statistically significant among the number of PIED cases in the animal population examined. Results: In the time period examined (2017-2022), a total of 366 cases of PIED were found in 342 dogs and 24 cats, respectively, for a total of 638 PIED lesions in dogs and 43 PIED lesions. in cats. The analysis of the data relating to the first three years (2017-2019) highlighted a total number (frequency; 95% confidence interval) of dogs affected by at least one PIED of 167 (49.12%; 95% CI: 43, 78% - 54.46%), for a total of 317 PIED lesions; 173 subjects (50.88%; 95% CI: 45.54% - 56.22%) were not affected by PIED. The number (frequency; 95% confidence interval) of cats with at least one PIED was 9 (19.57%; 95% CI: 7.65% –31.48%), for a total of 13 PIED lesions; 37 (80.43%; 95% CI: 68.52% - 92.35%), were not affected by PIED. In the second three-year period (2020-2022), during eye examinations the number (frequency; 95% confidence interval) of dogs with at least one PIED was 175 (46.17%; 95% CI : 41.13% - 51.22%), for a total of 321 PIED lesions; 204 (53.83%; 95% CI: 48.78% - 58.87%), were not affected by PIED. The number (frequency; 95% confidence interval) of cats with at least one PIED was 15 (22.39%; 95% CI: 12.14% - 32.63%), for a total of 30 PIED injuries; 52 (77.61%; 95% CI: 67.37% - 87.86%), were not affected by PIED. Conclusions: In conclusion, this study contributes to the existing literature by providing epidemiological data regarding presumed inherited ocular pathologies in dogs and cats and their clinical presentation. Clinicians should be aware that canine and feline breeds frequently suffer PIED. Breeding programs should be directed at limiting such disorders.